Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
new file mode 100644
index 0000000..30ab7b6
--- /dev/null
+++ b/net/ipv4/ip_output.c
@@ -0,0 +1,1359 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * The Internet Protocol (IP) output module.
+ *
+ * Version: $Id: ip_output.c,v 1.100 2002/02/01 22:01:03 davem Exp $
+ *
+ * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Donald Becker, <becker@super.org>
+ * Alan Cox, <Alan.Cox@linux.org>
+ * Richard Underwood
+ * Stefan Becker, <stefanb@yello.ping.de>
+ * Jorge Cwik, <jorge@laser.satlink.net>
+ * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ * Hirokazu Takahashi, <taka@valinux.co.jp>
+ *
+ * See ip_input.c for original log
+ *
+ * Fixes:
+ * Alan Cox : Missing nonblock feature in ip_build_xmit.
+ * Mike Kilburn : htons() missing in ip_build_xmit.
+ * Bradford Johnson: Fix faulty handling of some frames when
+ * no route is found.
+ * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit
+ * (in case if packet not accepted by
+ * output firewall rules)
+ * Mike McLagan : Routing by source
+ * Alexey Kuznetsov: use new route cache
+ * Andi Kleen: Fix broken PMTU recovery and remove
+ * some redundant tests.
+ * Vitaly E. Lavrov : Transparent proxy revived after year coma.
+ * Andi Kleen : Replace ip_reply with ip_send_reply.
+ * Andi Kleen : Split fast and slow ip_build_xmit path
+ * for decreased register pressure on x86
+ * and more readibility.
+ * Marc Boucher : When call_out_firewall returns FW_QUEUE,
+ * silently drop skb instead of failing with -EPERM.
+ * Detlev Wengorz : Copy protocol for fragments.
+ * Hirokazu Takahashi: HW checksumming for outgoing UDP
+ * datagrams.
+ * Hirokazu Takahashi: sendfile() on UDP works now.
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/config.h>
+
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/icmp.h>
+#include <net/raw.h>
+#include <net/checksum.h>
+#include <net/inetpeer.h>
+#include <net/checksum.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_bridge.h>
+#include <linux/mroute.h>
+#include <linux/netlink.h>
+
+/*
+ * Shall we try to damage output packets if routing dev changes?
+ */
+
+int sysctl_ip_dynaddr;
+int sysctl_ip_default_ttl = IPDEFTTL;
+
+/* Generate a checksum for an outgoing IP datagram. */
+__inline__ void ip_send_check(struct iphdr *iph)
+{
+ iph->check = 0;
+ iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+}
+
+/* dev_loopback_xmit for use with netfilter. */
+static int ip_dev_loopback_xmit(struct sk_buff *newskb)
+{
+ newskb->mac.raw = newskb->data;
+ __skb_pull(newskb, newskb->nh.raw - newskb->data);
+ newskb->pkt_type = PACKET_LOOPBACK;
+ newskb->ip_summed = CHECKSUM_UNNECESSARY;
+ BUG_TRAP(newskb->dst);
+
+#ifdef CONFIG_NETFILTER_DEBUG
+ nf_debug_ip_loopback_xmit(newskb);
+#endif
+ netif_rx(newskb);
+ return 0;
+}
+
+static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
+{
+ int ttl = inet->uc_ttl;
+
+ if (ttl < 0)
+ ttl = dst_metric(dst, RTAX_HOPLIMIT);
+ return ttl;
+}
+
+/*
+ * Add an ip header to a skbuff and send it out.
+ *
+ */
+int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
+ u32 saddr, u32 daddr, struct ip_options *opt)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct rtable *rt = (struct rtable *)skb->dst;
+ struct iphdr *iph;
+
+ /* Build the IP header. */
+ if (opt)
+ iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr) + opt->optlen);
+ else
+ iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr));
+
+ iph->version = 4;
+ iph->ihl = 5;
+ iph->tos = inet->tos;
+ if (ip_dont_fragment(sk, &rt->u.dst))
+ iph->frag_off = htons(IP_DF);
+ else
+ iph->frag_off = 0;
+ iph->ttl = ip_select_ttl(inet, &rt->u.dst);
+ iph->daddr = rt->rt_dst;
+ iph->saddr = rt->rt_src;
+ iph->protocol = sk->sk_protocol;
+ iph->tot_len = htons(skb->len);
+ ip_select_ident(iph, &rt->u.dst, sk);
+ skb->nh.iph = iph;
+
+ if (opt && opt->optlen) {
+ iph->ihl += opt->optlen>>2;
+ ip_options_build(skb, opt, daddr, rt, 0);
+ }
+ ip_send_check(iph);
+
+ skb->priority = sk->sk_priority;
+
+ /* Send it out. */
+ return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
+ dst_output);
+}
+
+static inline int ip_finish_output2(struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb->dst;
+ struct hh_cache *hh = dst->hh;
+ struct net_device *dev = dst->dev;
+ int hh_len = LL_RESERVED_SPACE(dev);
+
+ /* Be paranoid, rather than too clever. */
+ if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
+ struct sk_buff *skb2;
+
+ skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
+ if (skb2 == NULL) {
+ kfree_skb(skb);
+ return -ENOMEM;
+ }
+ if (skb->sk)
+ skb_set_owner_w(skb2, skb->sk);
+ kfree_skb(skb);
+ skb = skb2;
+ }
+
+#ifdef CONFIG_NETFILTER_DEBUG
+ nf_debug_ip_finish_output2(skb);
+#endif /*CONFIG_NETFILTER_DEBUG*/
+
+ if (hh) {
+ int hh_alen;
+
+ read_lock_bh(&hh->hh_lock);
+ hh_alen = HH_DATA_ALIGN(hh->hh_len);
+ memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
+ read_unlock_bh(&hh->hh_lock);
+ skb_push(skb, hh->hh_len);
+ return hh->hh_output(skb);
+ } else if (dst->neighbour)
+ return dst->neighbour->output(skb);
+
+ if (net_ratelimit())
+ printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
+ kfree_skb(skb);
+ return -EINVAL;
+}
+
+int ip_finish_output(struct sk_buff *skb)
+{
+ struct net_device *dev = skb->dst->dev;
+
+ skb->dev = dev;
+ skb->protocol = htons(ETH_P_IP);
+
+ return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev,
+ ip_finish_output2);
+}
+
+int ip_mc_output(struct sk_buff *skb)
+{
+ struct sock *sk = skb->sk;
+ struct rtable *rt = (struct rtable*)skb->dst;
+ struct net_device *dev = rt->u.dst.dev;
+
+ /*
+ * If the indicated interface is up and running, send the packet.
+ */
+ IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
+
+ skb->dev = dev;
+ skb->protocol = htons(ETH_P_IP);
+
+ /*
+ * Multicasts are looped back for other local users
+ */
+
+ if (rt->rt_flags&RTCF_MULTICAST) {
+ if ((!sk || inet_sk(sk)->mc_loop)
+#ifdef CONFIG_IP_MROUTE
+ /* Small optimization: do not loopback not local frames,
+ which returned after forwarding; they will be dropped
+ by ip_mr_input in any case.
+ Note, that local frames are looped back to be delivered
+ to local recipients.
+
+ This check is duplicated in ip_mr_input at the moment.
+ */
+ && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED))
+#endif
+ ) {
+ struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+ if (newskb)
+ NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
+ newskb->dev,
+ ip_dev_loopback_xmit);
+ }
+
+ /* Multicasts with ttl 0 must not go beyond the host */
+
+ if (skb->nh.iph->ttl == 0) {
+ kfree_skb(skb);
+ return 0;
+ }
+ }
+
+ if (rt->rt_flags&RTCF_BROADCAST) {
+ struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+ if (newskb)
+ NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
+ newskb->dev, ip_dev_loopback_xmit);
+ }
+
+ if (skb->len > dst_mtu(&rt->u.dst))
+ return ip_fragment(skb, ip_finish_output);
+ else
+ return ip_finish_output(skb);
+}
+
+int ip_output(struct sk_buff *skb)
+{
+ IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
+
+ if (skb->len > dst_mtu(skb->dst) && !skb_shinfo(skb)->tso_size)
+ return ip_fragment(skb, ip_finish_output);
+ else
+ return ip_finish_output(skb);
+}
+
+int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
+{
+ struct sock *sk = skb->sk;
+ struct inet_sock *inet = inet_sk(sk);
+ struct ip_options *opt = inet->opt;
+ struct rtable *rt;
+ struct iphdr *iph;
+
+ /* Skip all of this if the packet is already routed,
+ * f.e. by something like SCTP.
+ */
+ rt = (struct rtable *) skb->dst;
+ if (rt != NULL)
+ goto packet_routed;
+
+ /* Make sure we can route this packet. */
+ rt = (struct rtable *)__sk_dst_check(sk, 0);
+ if (rt == NULL) {
+ u32 daddr;
+
+ /* Use correct destination address if we have options. */
+ daddr = inet->daddr;
+ if(opt && opt->srr)
+ daddr = opt->faddr;
+
+ {
+ struct flowi fl = { .oif = sk->sk_bound_dev_if,
+ .nl_u = { .ip4_u =
+ { .daddr = daddr,
+ .saddr = inet->saddr,
+ .tos = RT_CONN_FLAGS(sk) } },
+ .proto = sk->sk_protocol,
+ .uli_u = { .ports =
+ { .sport = inet->sport,
+ .dport = inet->dport } } };
+
+ /* If this fails, retransmit mechanism of transport layer will
+ * keep trying until route appears or the connection times
+ * itself out.
+ */
+ if (ip_route_output_flow(&rt, &fl, sk, 0))
+ goto no_route;
+ }
+ __sk_dst_set(sk, &rt->u.dst);
+ tcp_v4_setup_caps(sk, &rt->u.dst);
+ }
+ skb->dst = dst_clone(&rt->u.dst);
+
+packet_routed:
+ if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+ goto no_route;
+
+ /* OK, we know where to send it, allocate and build IP header. */
+ iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+ *((__u16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
+ iph->tot_len = htons(skb->len);
+ if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
+ iph->frag_off = htons(IP_DF);
+ else
+ iph->frag_off = 0;
+ iph->ttl = ip_select_ttl(inet, &rt->u.dst);
+ iph->protocol = sk->sk_protocol;
+ iph->saddr = rt->rt_src;
+ iph->daddr = rt->rt_dst;
+ skb->nh.iph = iph;
+ /* Transport layer set skb->h.foo itself. */
+
+ if (opt && opt->optlen) {
+ iph->ihl += opt->optlen >> 2;
+ ip_options_build(skb, opt, inet->daddr, rt, 0);
+ }
+
+ ip_select_ident_more(iph, &rt->u.dst, sk, skb_shinfo(skb)->tso_segs);
+
+ /* Add an IP checksum. */
+ ip_send_check(iph);
+
+ skb->priority = sk->sk_priority;
+
+ return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
+ dst_output);
+
+no_route:
+ IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
+ kfree_skb(skb);
+ return -EHOSTUNREACH;
+}
+
+
+static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
+{
+ to->pkt_type = from->pkt_type;
+ to->priority = from->priority;
+ to->protocol = from->protocol;
+ to->security = from->security;
+ dst_release(to->dst);
+ to->dst = dst_clone(from->dst);
+ to->dev = from->dev;
+
+ /* Copy the flags to each fragment. */
+ IPCB(to)->flags = IPCB(from)->flags;
+
+#ifdef CONFIG_NET_SCHED
+ to->tc_index = from->tc_index;
+#endif
+#ifdef CONFIG_NETFILTER
+ to->nfmark = from->nfmark;
+ to->nfcache = from->nfcache;
+ /* Connection association is same as pre-frag packet */
+ nf_conntrack_put(to->nfct);
+ to->nfct = from->nfct;
+ nf_conntrack_get(to->nfct);
+ to->nfctinfo = from->nfctinfo;
+#ifdef CONFIG_BRIDGE_NETFILTER
+ nf_bridge_put(to->nf_bridge);
+ to->nf_bridge = from->nf_bridge;
+ nf_bridge_get(to->nf_bridge);
+#endif
+#ifdef CONFIG_NETFILTER_DEBUG
+ to->nf_debug = from->nf_debug;
+#endif
+#endif
+}
+
+/*
+ * This IP datagram is too large to be sent in one piece. Break it up into
+ * smaller pieces (each of size equal to IP header plus
+ * a block of the data of the original IP data part) that will yet fit in a
+ * single device frame, and queue such a frame for sending.
+ */
+
+int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
+{
+ struct iphdr *iph;
+ int raw = 0;
+ int ptr;
+ struct net_device *dev;
+ struct sk_buff *skb2;
+ unsigned int mtu, hlen, left, len, ll_rs;
+ int offset;
+ int not_last_frag;
+ struct rtable *rt = (struct rtable*)skb->dst;
+ int err = 0;
+
+ dev = rt->u.dst.dev;
+
+ /*
+ * Point into the IP datagram header.
+ */
+
+ iph = skb->nh.iph;
+
+ if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+ htonl(dst_mtu(&rt->u.dst)));
+ kfree_skb(skb);
+ return -EMSGSIZE;
+ }
+
+ /*
+ * Setup starting values.
+ */
+
+ hlen = iph->ihl * 4;
+ mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */
+
+ /* When frag_list is given, use it. First, check its validity:
+ * some transformers could create wrong frag_list or break existing
+ * one, it is not prohibited. In this case fall back to copying.
+ *
+ * LATER: this step can be merged to real generation of fragments,
+ * we can switch to copy when see the first bad fragment.
+ */
+ if (skb_shinfo(skb)->frag_list) {
+ struct sk_buff *frag;
+ int first_len = skb_pagelen(skb);
+
+ if (first_len - hlen > mtu ||
+ ((first_len - hlen) & 7) ||
+ (iph->frag_off & htons(IP_MF|IP_OFFSET)) ||
+ skb_cloned(skb))
+ goto slow_path;
+
+ for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
+ /* Correct geometry. */
+ if (frag->len > mtu ||
+ ((frag->len & 7) && frag->next) ||
+ skb_headroom(frag) < hlen)
+ goto slow_path;
+
+ /* Partially cloned skb? */
+ if (skb_shared(frag))
+ goto slow_path;
+ }
+
+ /* Everything is OK. Generate! */
+
+ err = 0;
+ offset = 0;
+ frag = skb_shinfo(skb)->frag_list;
+ skb_shinfo(skb)->frag_list = NULL;
+ skb->data_len = first_len - skb_headlen(skb);
+ skb->len = first_len;
+ iph->tot_len = htons(first_len);
+ iph->frag_off = htons(IP_MF);
+ ip_send_check(iph);
+
+ for (;;) {
+ /* Prepare header of the next frame,
+ * before previous one went down. */
+ if (frag) {
+ frag->ip_summed = CHECKSUM_NONE;
+ frag->h.raw = frag->data;
+ frag->nh.raw = __skb_push(frag, hlen);
+ memcpy(frag->nh.raw, iph, hlen);
+ iph = frag->nh.iph;
+ iph->tot_len = htons(frag->len);
+ ip_copy_metadata(frag, skb);
+ if (offset == 0)
+ ip_options_fragment(frag);
+ offset += skb->len - hlen;
+ iph->frag_off = htons(offset>>3);
+ if (frag->next != NULL)
+ iph->frag_off |= htons(IP_MF);
+ /* Ready, complete checksum */
+ ip_send_check(iph);
+ }
+
+ err = output(skb);
+
+ if (err || !frag)
+ break;
+
+ skb = frag;
+ frag = skb->next;
+ skb->next = NULL;
+ }
+
+ if (err == 0) {
+ IP_INC_STATS(IPSTATS_MIB_FRAGOKS);
+ return 0;
+ }
+
+ while (frag) {
+ skb = frag->next;
+ kfree_skb(frag);
+ frag = skb;
+ }
+ IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ return err;
+ }
+
+slow_path:
+ left = skb->len - hlen; /* Space per frame */
+ ptr = raw + hlen; /* Where to start from */
+
+#ifdef CONFIG_BRIDGE_NETFILTER
+ /* for bridged IP traffic encapsulated inside f.e. a vlan header,
+ * we need to make room for the encapsulating header */
+ ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, nf_bridge_pad(skb));
+ mtu -= nf_bridge_pad(skb);
+#else
+ ll_rs = LL_RESERVED_SPACE(rt->u.dst.dev);
+#endif
+ /*
+ * Fragment the datagram.
+ */
+
+ offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3;
+ not_last_frag = iph->frag_off & htons(IP_MF);
+
+ /*
+ * Keep copying data until we run out.
+ */
+
+ while(left > 0) {
+ len = left;
+ /* IF: it doesn't fit, use 'mtu' - the data space left */
+ if (len > mtu)
+ len = mtu;
+ /* IF: we are not sending upto and including the packet end
+ then align the next start on an eight byte boundary */
+ if (len < left) {
+ len &= ~7;
+ }
+ /*
+ * Allocate buffer.
+ */
+
+ if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) {
+ NETDEBUG(printk(KERN_INFO "IP: frag: no memory for new fragment!\n"));
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /*
+ * Set up data on packet
+ */
+
+ ip_copy_metadata(skb2, skb);
+ skb_reserve(skb2, ll_rs);
+ skb_put(skb2, len + hlen);
+ skb2->nh.raw = skb2->data;
+ skb2->h.raw = skb2->data + hlen;
+
+ /*
+ * Charge the memory for the fragment to any owner
+ * it might possess
+ */
+
+ if (skb->sk)
+ skb_set_owner_w(skb2, skb->sk);
+
+ /*
+ * Copy the packet header into the new buffer.
+ */
+
+ memcpy(skb2->nh.raw, skb->data, hlen);
+
+ /*
+ * Copy a block of the IP datagram.
+ */
+ if (skb_copy_bits(skb, ptr, skb2->h.raw, len))
+ BUG();
+ left -= len;
+
+ /*
+ * Fill in the new header fields.
+ */
+ iph = skb2->nh.iph;
+ iph->frag_off = htons((offset >> 3));
+
+ /* ANK: dirty, but effective trick. Upgrade options only if
+ * the segment to be fragmented was THE FIRST (otherwise,
+ * options are already fixed) and make it ONCE
+ * on the initial skb, so that all the following fragments
+ * will inherit fixed options.
+ */
+ if (offset == 0)
+ ip_options_fragment(skb);
+
+ /*
+ * Added AC : If we are fragmenting a fragment that's not the
+ * last fragment then keep MF on each bit
+ */
+ if (left > 0 || not_last_frag)
+ iph->frag_off |= htons(IP_MF);
+ ptr += len;
+ offset += len;
+
+ /*
+ * Put this fragment into the sending queue.
+ */
+
+ IP_INC_STATS(IPSTATS_MIB_FRAGCREATES);
+
+ iph->tot_len = htons(len + hlen);
+
+ ip_send_check(iph);
+
+ err = output(skb2);
+ if (err)
+ goto fail;
+ }
+ kfree_skb(skb);
+ IP_INC_STATS(IPSTATS_MIB_FRAGOKS);
+ return err;
+
+fail:
+ kfree_skb(skb);
+ IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
+ return err;
+}
+
+int
+ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
+{
+ struct iovec *iov = from;
+
+ if (skb->ip_summed == CHECKSUM_HW) {
+ if (memcpy_fromiovecend(to, iov, offset, len) < 0)
+ return -EFAULT;
+ } else {
+ unsigned int csum = 0;
+ if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0)
+ return -EFAULT;
+ skb->csum = csum_block_add(skb->csum, csum, odd);
+ }
+ return 0;
+}
+
+static inline unsigned int
+csum_page(struct page *page, int offset, int copy)
+{
+ char *kaddr;
+ unsigned int csum;
+ kaddr = kmap(page);
+ csum = csum_partial(kaddr + offset, copy, 0);
+ kunmap(page);
+ return csum;
+}
+
+/*
+ * ip_append_data() and ip_append_page() can make one large IP datagram
+ * from many pieces of data. Each pieces will be holded on the socket
+ * until ip_push_pending_frames() is called. Each piece can be a page
+ * or non-page data.
+ *
+ * Not only UDP, other transport protocols - e.g. raw sockets - can use
+ * this interface potentially.
+ *
+ * LATER: length must be adjusted by pad at tail, when it is required.
+ */
+int ip_append_data(struct sock *sk,
+ int getfrag(void *from, char *to, int offset, int len,
+ int odd, struct sk_buff *skb),
+ void *from, int length, int transhdrlen,
+ struct ipcm_cookie *ipc, struct rtable *rt,
+ unsigned int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct sk_buff *skb;
+
+ struct ip_options *opt = NULL;
+ int hh_len;
+ int exthdrlen;
+ int mtu;
+ int copy;
+ int err;
+ int offset = 0;
+ unsigned int maxfraglen, fragheaderlen;
+ int csummode = CHECKSUM_NONE;
+
+ if (flags&MSG_PROBE)
+ return 0;
+
+ if (skb_queue_empty(&sk->sk_write_queue)) {
+ /*
+ * setup for corking.
+ */
+ opt = ipc->opt;
+ if (opt) {
+ if (inet->cork.opt == NULL) {
+ inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation);
+ if (unlikely(inet->cork.opt == NULL))
+ return -ENOBUFS;
+ }
+ memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen);
+ inet->cork.flags |= IPCORK_OPT;
+ inet->cork.addr = ipc->addr;
+ }
+ dst_hold(&rt->u.dst);
+ inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
+ inet->cork.rt = rt;
+ inet->cork.length = 0;
+ sk->sk_sndmsg_page = NULL;
+ sk->sk_sndmsg_off = 0;
+ if ((exthdrlen = rt->u.dst.header_len) != 0) {
+ length += exthdrlen;
+ transhdrlen += exthdrlen;
+ }
+ } else {
+ rt = inet->cork.rt;
+ if (inet->cork.flags & IPCORK_OPT)
+ opt = inet->cork.opt;
+
+ transhdrlen = 0;
+ exthdrlen = 0;
+ mtu = inet->cork.fragsize;
+ }
+ hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
+
+ fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
+ maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
+
+ if (inet->cork.length + length > 0xFFFF - fragheaderlen) {
+ ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen);
+ return -EMSGSIZE;
+ }
+
+ /*
+ * transhdrlen > 0 means that this is the first fragment and we wish
+ * it won't be fragmented in the future.
+ */
+ if (transhdrlen &&
+ length + fragheaderlen <= mtu &&
+ rt->u.dst.dev->features&(NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM) &&
+ !exthdrlen)
+ csummode = CHECKSUM_HW;
+
+ inet->cork.length += length;
+
+ /* So, what's going on in the loop below?
+ *
+ * We use calculated fragment length to generate chained skb,
+ * each of segments is IP fragment ready for sending to network after
+ * adding appropriate IP header.
+ */
+
+ if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ goto alloc_new_skb;
+
+ while (length > 0) {
+ /* Check if the remaining data fits into current packet. */
+ copy = mtu - skb->len;
+ if (copy < length)
+ copy = maxfraglen - skb->len;
+ if (copy <= 0) {
+ char *data;
+ unsigned int datalen;
+ unsigned int fraglen;
+ unsigned int fraggap;
+ unsigned int alloclen;
+ struct sk_buff *skb_prev;
+alloc_new_skb:
+ skb_prev = skb;
+ if (skb_prev)
+ fraggap = skb_prev->len - maxfraglen;
+ else
+ fraggap = 0;
+
+ /*
+ * If remaining data exceeds the mtu,
+ * we know we need more fragment(s).
+ */
+ datalen = length + fraggap;
+ if (datalen > mtu - fragheaderlen)
+ datalen = maxfraglen - fragheaderlen;
+ fraglen = datalen + fragheaderlen;
+
+ if ((flags & MSG_MORE) &&
+ !(rt->u.dst.dev->features&NETIF_F_SG))
+ alloclen = mtu;
+ else
+ alloclen = datalen + fragheaderlen;
+
+ /* The last fragment gets additional space at tail.
+ * Note, with MSG_MORE we overallocate on fragments,
+ * because we have no idea what fragment will be
+ * the last.
+ */
+ if (datalen == length)
+ alloclen += rt->u.dst.trailer_len;
+
+ if (transhdrlen) {
+ skb = sock_alloc_send_skb(sk,
+ alloclen + hh_len + 15,
+ (flags & MSG_DONTWAIT), &err);
+ } else {
+ skb = NULL;
+ if (atomic_read(&sk->sk_wmem_alloc) <=
+ 2 * sk->sk_sndbuf)
+ skb = sock_wmalloc(sk,
+ alloclen + hh_len + 15, 1,
+ sk->sk_allocation);
+ if (unlikely(skb == NULL))
+ err = -ENOBUFS;
+ }
+ if (skb == NULL)
+ goto error;
+
+ /*
+ * Fill in the control structures
+ */
+ skb->ip_summed = csummode;
+ skb->csum = 0;
+ skb_reserve(skb, hh_len);
+
+ /*
+ * Find where to start putting bytes.
+ */
+ data = skb_put(skb, fraglen);
+ skb->nh.raw = data + exthdrlen;
+ data += fragheaderlen;
+ skb->h.raw = data + exthdrlen;
+
+ if (fraggap) {
+ skb->csum = skb_copy_and_csum_bits(
+ skb_prev, maxfraglen,
+ data + transhdrlen, fraggap, 0);
+ skb_prev->csum = csum_sub(skb_prev->csum,
+ skb->csum);
+ data += fraggap;
+ skb_trim(skb_prev, maxfraglen);
+ }
+
+ copy = datalen - transhdrlen - fraggap;
+ if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+ err = -EFAULT;
+ kfree_skb(skb);
+ goto error;
+ }
+
+ offset += copy;
+ length -= datalen - fraggap;
+ transhdrlen = 0;
+ exthdrlen = 0;
+ csummode = CHECKSUM_NONE;
+
+ /*
+ * Put the packet on the pending queue.
+ */
+ __skb_queue_tail(&sk->sk_write_queue, skb);
+ continue;
+ }
+
+ if (copy > length)
+ copy = length;
+
+ if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
+ unsigned int off;
+
+ off = skb->len;
+ if (getfrag(from, skb_put(skb, copy),
+ offset, copy, off, skb) < 0) {
+ __skb_trim(skb, off);
+ err = -EFAULT;
+ goto error;
+ }
+ } else {
+ int i = skb_shinfo(skb)->nr_frags;
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
+ struct page *page = sk->sk_sndmsg_page;
+ int off = sk->sk_sndmsg_off;
+ unsigned int left;
+
+ if (page && (left = PAGE_SIZE - off) > 0) {
+ if (copy >= left)
+ copy = left;
+ if (page != frag->page) {
+ if (i == MAX_SKB_FRAGS) {
+ err = -EMSGSIZE;
+ goto error;
+ }
+ get_page(page);
+ skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
+ frag = &skb_shinfo(skb)->frags[i];
+ }
+ } else if (i < MAX_SKB_FRAGS) {
+ if (copy > PAGE_SIZE)
+ copy = PAGE_SIZE;
+ page = alloc_pages(sk->sk_allocation, 0);
+ if (page == NULL) {
+ err = -ENOMEM;
+ goto error;
+ }
+ sk->sk_sndmsg_page = page;
+ sk->sk_sndmsg_off = 0;
+
+ skb_fill_page_desc(skb, i, page, 0, 0);
+ frag = &skb_shinfo(skb)->frags[i];
+ skb->truesize += PAGE_SIZE;
+ atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
+ } else {
+ err = -EMSGSIZE;
+ goto error;
+ }
+ if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
+ err = -EFAULT;
+ goto error;
+ }
+ sk->sk_sndmsg_off += copy;
+ frag->size += copy;
+ skb->len += copy;
+ skb->data_len += copy;
+ }
+ offset += copy;
+ length -= copy;
+ }
+
+ return 0;
+
+error:
+ inet->cork.length -= length;
+ IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ return err;
+}
+
+ssize_t ip_append_page(struct sock *sk, struct page *page,
+ int offset, size_t size, int flags)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct sk_buff *skb;
+ struct rtable *rt;
+ struct ip_options *opt = NULL;
+ int hh_len;
+ int mtu;
+ int len;
+ int err;
+ unsigned int maxfraglen, fragheaderlen, fraggap;
+
+ if (inet->hdrincl)
+ return -EPERM;
+
+ if (flags&MSG_PROBE)
+ return 0;
+
+ if (skb_queue_empty(&sk->sk_write_queue))
+ return -EINVAL;
+
+ rt = inet->cork.rt;
+ if (inet->cork.flags & IPCORK_OPT)
+ opt = inet->cork.opt;
+
+ if (!(rt->u.dst.dev->features&NETIF_F_SG))
+ return -EOPNOTSUPP;
+
+ hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
+ mtu = inet->cork.fragsize;
+
+ fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
+ maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
+
+ if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
+ ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
+ return -EMSGSIZE;
+ }
+
+ if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+ return -EINVAL;
+
+ inet->cork.length += size;
+
+ while (size > 0) {
+ int i;
+
+ /* Check if the remaining data fits into current packet. */
+ len = mtu - skb->len;
+ if (len < size)
+ len = maxfraglen - skb->len;
+ if (len <= 0) {
+ struct sk_buff *skb_prev;
+ char *data;
+ struct iphdr *iph;
+ int alloclen;
+
+ skb_prev = skb;
+ if (skb_prev)
+ fraggap = skb_prev->len - maxfraglen;
+ else
+ fraggap = 0;
+
+ alloclen = fragheaderlen + hh_len + fraggap + 15;
+ skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation);
+ if (unlikely(!skb)) {
+ err = -ENOBUFS;
+ goto error;
+ }
+
+ /*
+ * Fill in the control structures
+ */
+ skb->ip_summed = CHECKSUM_NONE;
+ skb->csum = 0;
+ skb_reserve(skb, hh_len);
+
+ /*
+ * Find where to start putting bytes.
+ */
+ data = skb_put(skb, fragheaderlen + fraggap);
+ skb->nh.iph = iph = (struct iphdr *)data;
+ data += fragheaderlen;
+ skb->h.raw = data;
+
+ if (fraggap) {
+ skb->csum = skb_copy_and_csum_bits(
+ skb_prev, maxfraglen,
+ data, fraggap, 0);
+ skb_prev->csum = csum_sub(skb_prev->csum,
+ skb->csum);
+ skb_trim(skb_prev, maxfraglen);
+ }
+
+ /*
+ * Put the packet on the pending queue.
+ */
+ __skb_queue_tail(&sk->sk_write_queue, skb);
+ continue;
+ }
+
+ i = skb_shinfo(skb)->nr_frags;
+ if (len > size)
+ len = size;
+ if (skb_can_coalesce(skb, i, page, offset)) {
+ skb_shinfo(skb)->frags[i-1].size += len;
+ } else if (i < MAX_SKB_FRAGS) {
+ get_page(page);
+ skb_fill_page_desc(skb, i, page, offset, len);
+ } else {
+ err = -EMSGSIZE;
+ goto error;
+ }
+
+ if (skb->ip_summed == CHECKSUM_NONE) {
+ unsigned int csum;
+ csum = csum_page(page, offset, len);
+ skb->csum = csum_block_add(skb->csum, csum, skb->len);
+ }
+
+ skb->len += len;
+ skb->data_len += len;
+ offset += len;
+ size -= len;
+ }
+ return 0;
+
+error:
+ inet->cork.length -= size;
+ IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ return err;
+}
+
+/*
+ * Combined all pending IP fragments on the socket as one IP datagram
+ * and push them out.
+ */
+int ip_push_pending_frames(struct sock *sk)
+{
+ struct sk_buff *skb, *tmp_skb;
+ struct sk_buff **tail_skb;
+ struct inet_sock *inet = inet_sk(sk);
+ struct ip_options *opt = NULL;
+ struct rtable *rt = inet->cork.rt;
+ struct iphdr *iph;
+ int df = 0;
+ __u8 ttl;
+ int err = 0;
+
+ if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
+ goto out;
+ tail_skb = &(skb_shinfo(skb)->frag_list);
+
+ /* move skb->data to ip header from ext header */
+ if (skb->data < skb->nh.raw)
+ __skb_pull(skb, skb->nh.raw - skb->data);
+ while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
+ __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
+ *tail_skb = tmp_skb;
+ tail_skb = &(tmp_skb->next);
+ skb->len += tmp_skb->len;
+ skb->data_len += tmp_skb->len;
+ skb->truesize += tmp_skb->truesize;
+ __sock_put(tmp_skb->sk);
+ tmp_skb->destructor = NULL;
+ tmp_skb->sk = NULL;
+ }
+
+ /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow
+ * to fragment the frame generated here. No matter, what transforms
+ * how transforms change size of the packet, it will come out.
+ */
+ if (inet->pmtudisc != IP_PMTUDISC_DO)
+ skb->local_df = 1;
+
+ /* DF bit is set when we want to see DF on outgoing frames.
+ * If local_df is set too, we still allow to fragment this frame
+ * locally. */
+ if (inet->pmtudisc == IP_PMTUDISC_DO ||
+ (skb->len <= dst_mtu(&rt->u.dst) &&
+ ip_dont_fragment(sk, &rt->u.dst)))
+ df = htons(IP_DF);
+
+ if (inet->cork.flags & IPCORK_OPT)
+ opt = inet->cork.opt;
+
+ if (rt->rt_type == RTN_MULTICAST)
+ ttl = inet->mc_ttl;
+ else
+ ttl = ip_select_ttl(inet, &rt->u.dst);
+
+ iph = (struct iphdr *)skb->data;
+ iph->version = 4;
+ iph->ihl = 5;
+ if (opt) {
+ iph->ihl += opt->optlen>>2;
+ ip_options_build(skb, opt, inet->cork.addr, rt, 0);
+ }
+ iph->tos = inet->tos;
+ iph->tot_len = htons(skb->len);
+ iph->frag_off = df;
+ if (!df) {
+ __ip_select_ident(iph, &rt->u.dst, 0);
+ } else {
+ iph->id = htons(inet->id++);
+ }
+ iph->ttl = ttl;
+ iph->protocol = sk->sk_protocol;
+ iph->saddr = rt->rt_src;
+ iph->daddr = rt->rt_dst;
+ ip_send_check(iph);
+
+ skb->priority = sk->sk_priority;
+ skb->dst = dst_clone(&rt->u.dst);
+
+ /* Netfilter gets whole the not fragmented skb. */
+ err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL,
+ skb->dst->dev, dst_output);
+ if (err) {
+ if (err > 0)
+ err = inet->recverr ? net_xmit_errno(err) : 0;
+ if (err)
+ goto error;
+ }
+
+out:
+ inet->cork.flags &= ~IPCORK_OPT;
+ if (inet->cork.opt) {
+ kfree(inet->cork.opt);
+ inet->cork.opt = NULL;
+ }
+ if (inet->cork.rt) {
+ ip_rt_put(inet->cork.rt);
+ inet->cork.rt = NULL;
+ }
+ return err;
+
+error:
+ IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
+ goto out;
+}
+
+/*
+ * Throw away all pending data on the socket.
+ */
+void ip_flush_pending_frames(struct sock *sk)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
+ kfree_skb(skb);
+
+ inet->cork.flags &= ~IPCORK_OPT;
+ if (inet->cork.opt) {
+ kfree(inet->cork.opt);
+ inet->cork.opt = NULL;
+ }
+ if (inet->cork.rt) {
+ ip_rt_put(inet->cork.rt);
+ inet->cork.rt = NULL;
+ }
+}
+
+
+/*
+ * Fetch data from kernel space and fill in checksum if needed.
+ */
+static int ip_reply_glue_bits(void *dptr, char *to, int offset,
+ int len, int odd, struct sk_buff *skb)
+{
+ unsigned int csum;
+
+ csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0);
+ skb->csum = csum_block_add(skb->csum, csum, odd);
+ return 0;
+}
+
+/*
+ * Generic function to send a packet as reply to another packet.
+ * Used to send TCP resets so far. ICMP should use this function too.
+ *
+ * Should run single threaded per socket because it uses the sock
+ * structure to pass arguments.
+ *
+ * LATER: switch from ip_build_xmit to ip_append_*
+ */
+void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
+ unsigned int len)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct {
+ struct ip_options opt;
+ char data[40];
+ } replyopts;
+ struct ipcm_cookie ipc;
+ u32 daddr;
+ struct rtable *rt = (struct rtable*)skb->dst;
+
+ if (ip_options_echo(&replyopts.opt, skb))
+ return;
+
+ daddr = ipc.addr = rt->rt_src;
+ ipc.opt = NULL;
+
+ if (replyopts.opt.optlen) {
+ ipc.opt = &replyopts.opt;
+
+ if (ipc.opt->srr)
+ daddr = replyopts.opt.faddr;
+ }
+
+ {
+ struct flowi fl = { .nl_u = { .ip4_u =
+ { .daddr = daddr,
+ .saddr = rt->rt_spec_dst,
+ .tos = RT_TOS(skb->nh.iph->tos) } },
+ /* Not quite clean, but right. */
+ .uli_u = { .ports =
+ { .sport = skb->h.th->dest,
+ .dport = skb->h.th->source } },
+ .proto = sk->sk_protocol };
+ if (ip_route_output_key(&rt, &fl))
+ return;
+ }
+
+ /* And let IP do all the hard work.
+
+ This chunk is not reenterable, hence spinlock.
+ Note that it uses the fact, that this function is called
+ with locally disabled BH and that sk cannot be already spinlocked.
+ */
+ bh_lock_sock(sk);
+ inet->tos = skb->nh.iph->tos;
+ sk->sk_priority = skb->priority;
+ sk->sk_protocol = skb->nh.iph->protocol;
+ ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
+ &ipc, rt, MSG_DONTWAIT);
+ if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
+ if (arg->csumoffset >= 0)
+ *((u16 *)skb->h.raw + arg->csumoffset) = csum_fold(csum_add(skb->csum, arg->csum));
+ skb->ip_summed = CHECKSUM_NONE;
+ ip_push_pending_frames(sk);
+ }
+
+ bh_unlock_sock(sk);
+
+ ip_rt_put(rt);
+}
+
+/*
+ * IP protocol layer initialiser
+ */
+
+static struct packet_type ip_packet_type = {
+ .type = __constant_htons(ETH_P_IP),
+ .func = ip_rcv,
+};
+
+/*
+ * IP registers the packet type and then calls the subprotocol initialisers
+ */
+
+void __init ip_init(void)
+{
+ dev_add_pack(&ip_packet_type);
+
+ ip_rt_init();
+ inet_initpeers();
+
+#if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS)
+ igmp_mc_proc_init();
+#endif
+}
+
+EXPORT_SYMBOL(ip_finish_output);
+EXPORT_SYMBOL(ip_fragment);
+EXPORT_SYMBOL(ip_generic_getfrag);
+EXPORT_SYMBOL(ip_queue_xmit);
+EXPORT_SYMBOL(ip_send_check);
+
+#ifdef CONFIG_SYSCTL
+EXPORT_SYMBOL(sysctl_ip_default_ttl);
+#endif